DIY rpi device for each room

I’m in the market for temperature sensors that I’d like to put in the 3 bedrooms of my house. I’d prefer something that plugs in as opposed to battery operated. I keep coming back to the sonoff and have a hard time getting past the reviews.

It got me wondering if I could do this with an rpi and add other features as well. For example smart speaker, motion sensor, maybe night light, maybe intercom?

Just trying to think outside the box. Does anyone have a project this in their home?

Room-assistant might fit your needs.
https://www.room-assistant.io/

I don’t use it my self. However I did read about how to use it, and it has features you are looking for.